/*设置背景图片*/
body {
    background: url(../images/back.jpg) no-repeat;
    background-size:cover;
    font-size: 15px;
}
/*给表单的边框设置大小,颜色和不透明度*/
.form {
    background: rgb(204, 200, 197, 0.6);
    width: 400px;
    margin: 150px auto;
    border-radius: 3%;
}
.form-horizontal{
    display: flex;
    flex-direction: column;
    align-items: center;
}
/*设置字体和大小*/
label {
    font-family: Arial;
    font-size: 15px;
}
/*当输入正确时,给输入框设置浅绿色*/
input.form-control:valid{
    background-color: mintcream;
}
/*当输入正确时,给输入框设置浅红色*/
input.form-control:invalid{
    background-color: #ffeeed;
}
/*设置图标为行内元素，并设置大小和颜色*/
.fas{
    display: inline-block;
    top: 31px;
    left: 10px;
    position: relative;
    color: #3e3b3b;
}
/*为几个输入框设置padding,防止和图标重合*/
input[type="text"],input[type="password"],input[type="email"]{
    padding-left:30px;
}
.form-title{
    padding-top:20px;
}

.button-group{
    padding-top: 20px;
    padding-bottom: 20px;
    display: flex; 
    justify-content: space-evenly;
}

.btn-login{
    display: flex;
    justify-content: center;
    margin-top: 10px;
    margin-bottom: 20px;
}